Onchocerciasis in Cattle and Associated Animals. ;>l 



extravasation of blood into the worm-tunnels, and the anterior end 

 of the female and most of the male were caseated. In the third 

 nodule there was also much extravasation into the worm-tunnels, 

 and caseation of nodule and worms, but the heads of both male and 

 female, and the tail of the male, were obtained, and served but 

 to confirm tho observations made in the body of this report on 

 nodules from Siam, provided by Mr. T. A. Ford, these worms 

 being certainly 0. gibsoni. 



One or two peculiarities in this specimen are specially note- 

 worthy, the remarkable distance (1.24 mm.) of the opening of the 

 vulva from the anterior end, even for 0. gibsoni, in which it is 

 often so much greater than in 0. indica (cf. Leiper's description of 

 1.23 mm.). Also in the male, are found a remarkably short, thin 

 oesophagus (length .314 mm., and diameter .0094 mm.), and a very 

 short " long " spicule (.138 mm.), which are quite unique even for 

 O. gibsoni. These features, with the abnormally thin head and body 

 of the male, emphasise the statement made in connection with the 

 previous material of 0. gibsoni from Siam, that where any special 

 variations from the average measurements of 0. gibsoni exist 

 therein, those variations are in an opposite direction to those mea- 

 surements which are characteristic of 0. indica. A similar state- 

 ment is true here id' the anal papillae, which are as follow : 

 R., preanal 0, adanal 2, postanal 1, caudal 2; 

 L., preanal 0, adanal 2, postanal 1, caudal 2, 

 making a total of five on each side — again a smaller number than 

 is usually found in 0. gibsoni. 



(b) The nodules from the buffalo differ somewhat in external 

 appearance from those found in cattle, the capsule of free nodules 

 being at times much thicker than in Bos indicus, and the fibrous 

 tissue much less compacted in the outer part of the capsule than in 

 either Bos taurus or Bos indicus, though at the same time it is 

 very tough and resistant to cutting or tearing. At other times, a 

 continuous capsule wall is absent, only a trifling amount of fibrous 

 tissue being present, and then forming long independent strands. 

 A quantity of muscular tissue, more or less degenerated, surrounds 

 the nodule in place of the ordinary capsule. Very frequently the 

 nodule is closely united with the skin (see Fig. 12). There may be 

 then also no true capsule wall, the nodule ( = worm-area only) 

 lying in the subcutaneous muscular tissue. There is present a very 

 small amount of white fibrous tissue forming long bundles emerging 

 irregularly from the worm-area and mingling with the fibrous tissue 

 of the subdermal layers. The trabeculae forming the walls of the 



